As is known in computer graphics, a two-dimensional image or texture can be applied to a three-dimensional geometry. For example, a two-dimensional photograph can be wrapped around a three-dimensional object. When this is done, seams on the three-dimensional geometry can occur.
FIG. 1 is a plan view of a two-dimensional image 100, and FIG. 2 is a plan view of a three-dimensional geometry 200 corresponding to the two-dimensional image 100 of FIG. 1. As seen in FIG. 1, the two-dimensional image 100 is a rectangle. A left edge 110 of the rectangle includes a column of the letter “L” and a right edge 120 of the rectangle includes a column of the letter “R.
To create the three-dimensional geometry 200 shown in FIG. 2, the left edge 110 of the two-dimensional rectangle 100 can be wrapped around to reach the right edge 120 of the two-dimensional rectangle 100. Then, as seen in FIG. 2, the resulting geometry 200 can be a cylinder with the left edge 210 of the rectangle (column of “L”) connecting with the right edge 220 of the rectangle (column of “R”). The connection of the left and right edges 210, 220 of the rectangle creates a seam 250 on the three-dimensional geometry 200.
When it is known in advance that a two-dimensional image will be mapped into a three-dimensional geometry, the two-dimensional image can be mapped or drawn in such a way to hide any resulting seams when the three-dimensional geometry is created. For example, FIG. 3 is a plan view of a two-dimensional image 300 with first and second cut-outs 315, 325 on respective first and second edges 310, 320 thereof. Each of the first and second cut-outs 315, 325 can have a semi-circular shape.
FIG. 4 is a plan view of a three-dimensional geometry 400 corresponding to the two-dimensional image 300 of FIG. 3. As seen in FIG. 4, when the left edge 310 of the two-dimensional rectangle 300 is wrapped around to reach the right edge 320 of the two-dimensional rectangle 300, the first and second cut-outs 415, 425 can meet on the seam 450 to form an aperture 430 having a circular shape. Thus, the seam 450 is hidden in the area of the circular aperture 430.
Problems arise when the shape of a three-dimensional geometry is not known in advance because, in these situations, the corresponding two-dimensional image cannot be mapped to hide resulting seams. For example, when a three-dimensional geometry is customized with decals, a corresponding two-dimensional image cannot be mapped in advance to hide seams created by the decals.
FIG. 5 is plan view of an exemplary two-dimensional image 500, and FIG. 6 is a plan view of a three dimensional structure 600 corresponding to the two-dimensional image 500 of FIG. 5. The first sub-image 510 in FIG. 5 corresponds to the top portion 610 of the structure 600 in FIG. 6, the second sub-image 520 in FIG. 5 corresponds to the middle portion 620 of the structure 600 in FIG. 6, and the third sub-image 530 in FIG. 5 corresponds to the bottom portion 6300 of the structure 600 in FIG. 6. As seen in FIG. 6, when a pattern or texture is applied to the image 500 in FIG. 5, a seam 650 results when the image with the is pattern mapped into the structure 600 of FIG. 6.
As seen in FIG. 7, a user can customize the two-dimensional image 700 by, for example, arbitrarily placing a decal 775 on the image 700 at any desired location. When the decal 775 is applied without accounting for seams, a structure 800 as is shown in FIG. 8 can result when the image 700 with the decal 775 is mapped onto a three-dimensional structure. That is, the decal 875 can be shown on the three-dimensional structure 800 incompletely, inaccurately, and/or with seams.
Systems and methods have been developed to address the above-identified problems. For example, decal projection has been used. In decal projection, the texture, including the shape and size, of a decal can be projected onto a three-dimensional structure. This is akin to shining a flashlight onto a three-dimensional structure and applying the decal anywhere the light hits. For example, if the flashlight projects a square light, then the resulting decal can be square and be rotated and sized.
However, decal projection has presented significant disadvantages. For example, shadows, such as where the three-dimensional structure occludes itself, can occur. Furthermore, bleeding of the decal onto the other side of the structure can occur, and bad stretching, for example, when the structure is parallel to light rays, can occur.
In view of the above, improved systems and methods are desired for resolving seams in computer graphics when two-dimensional image is applied to a three-dimensional structure.